The return of snow and freezing weather has stranded about 180,000 people in Yunnan province.
Heavy snow blocked about 14,000 km of roads, disrupting more than 12,000 passengers' on Sunday alone, a provincial transport department spokesman said. Many areas have been suffering from power outages, too.
Snowstorms have lashed the northern part of Yunnan since late January.
And though there was a respite during Spring Festival, the continuous inclement weather has damaged many roads.
Like much of southern and southwestern China, Yunnan had been recovering slowly from the worst winter in five decades when fresh snow on Thursday once again threw life out of gear.
Qujing, the second largest provincial city, closed six highways, cancelled buses plying on 42 routes and prevented about 800 motor vehicles from traveling. Transport in other cities, including Zhaotong and Diqing, too has been hit hard.
The provincial transport department has set up a repair-work force to ensure smooth road travel. But work has been hampered by the freezing weather on the plateau, poor facilities and shortage of money.
Many of the workers do not even have any special "anti-freezing" apparels and snow removing equipment because they have never needed them before.
The government is struggling to restore electricity supply in Qujing. Till Saturday, the city's 39 counties and townships, 90 percent of the total, were without electricity because the grids had suffered serious damage, government officials said.
More than 2 million people, 80 percent of the total, have been without electricity, with coal oil, candles, charcoal and coal cakes making a comeback in villages.
Blocked roads are preventing coal from being transported. As a result, most power plants have enough fuel for only two more days.
Qujing is the province's major industrial base, and has an installed power generating capacity of 5.4 million kilowatts, accounting for 56 percent of Yunnan's total. Heavy snow had snapped power supply on 20 lines by Saturday evening, even though workers were trying to fix them and repair the grids.
Yunnan is among the worst-hit provinces in southern China. The provincial department of civil affairs said on Saturday that 12 people had died, four were missing, and more than 10 million had been affected by the freezing weather.
Snowstorms have destroyed or damaged more than 4,000 houses, killed more than 300,000 cattle heads and birds, and ruined about 700,000 hectares of farmland.
Power supply on about 1,000 power lines had been cut off and 55 pylons had collapsed.
The local meteorological office has forecast that the extreme weather will continue for a few more days.